1.0 Field of the Invention
This invention relates, generally to apparatus for heating water, and more particularly to steam/water mixer.
2.0 Discussion of Related Art
A steam/water mixer of the type in question is known from earlier, hitherto unpublished patent application P 38 37 728.4-52. In this steam/water mixer, the temperature of the outflowing hot water varies by about 10.degree. C. in the event of changes in the counterpressure built up by the spatial height of the hot water hose and the outlet nozzle. Accordingly, the steam/water mixer according to the earlier patent application can only be used for cleaning and similar purposes, but not for heating reactors, stirred tanks, for example in pilot plants, and comparable systems due to the excessive variations in temperature.
3.0 Summary of the Invention
An object of the present invention is to reduce the temperature variations produced in a steam/water mixer of the type mentioned above to such an extent that the improved mixer is suitable for heating the above-mentioned containers and systems.
The steam/water mixer in one embodiment of the invention comprises an inlet for water; an inlet for steam; a vessel for mixing steam and water; an outlet for heated water from the mixing vessel; and a sintered material which is disposed in the mixing vessel between the steam inlet(s) and the water inlet(s), and which is arranged in such a way that the steam entering the mixing vessel only passes to the water inlet or to the outlet of the mixing vessel through the sintered material. The sintered material may be a ceramic or metal. Since the steam flows through the hollow cylinder before mixing and hence bubbles through the water in very fine dispersion, the lime present in the water also precipitates in very fine dispersion and does not form any scale. This finely dispersed lime is discharged from the steam/water mixer with the heated water. Since only fine-bubble steam and water are mixed in the mixing vessel, cavitation noise is also considerably reduced.
According to one embodiment of the invention, the temperature variation problem has been solved by including packings arranged in the space between the sintered material and the inner wall of the mixing vessel. The packings reduce the variations in temperature to around 2.degree. C. despite the varying spatial position of the outlet nozzle and the hot water hose. In addition, the noise level of 68.5 dB (A) generated by the mixer according to the earlier patent application is reduced to 63.5 dB (A) in the mixer according to the present invention for otherwise the same conditions. The mixer according to the invention can still be used for preparing hot water for cleaning and similar purposes. In addition, the mixer according to the invention can be used for heating containers and comparable systems, for example in laboratories, pilot plants and production plants.
The packing elements in one embodiment of the invention are preferably cylindrical in shape. It is particularly advantageous in this regard if the diameter and height of the packing elements are substantially the same. The word "substantially" in this context means that a difference of up to 10% lies within the scope of this embodiment of the invention.
In addition, in one embodiment of the invention the packing elements preferably consist of metal, more particularly stainless steel. Particularly effective noise reduction is obtained in this way.